Then I found a couple of similar plugins, studied them a bit, and, voila, the offspring of this endeavor: the Biblionet calibre plugin.
(Those not interested in code should download the plugin from here because the github zip adds an extra folder to the plugin and generates an error when trying to add it).

Installation
To install the plugin, open Calibre, go to Preferences>Change Calibre behavior, scroll down and locate in the Advanced section the Plugins icon. Click it and the following window will appear:
Choose “Load plugin from file”, answer ‘yes’ to the warning that will pop up, and you are done.

Use
The best option for mass entering and mass updating printed books in calibre IMHO is this:

Use a mobile phone barcode scanner app to read the isbn barcodes, or write them down, one per line, in a text file.

Then copy paste them in the relevant calibre dialog box (see picture) and fire the process.

The Future
This plugin is not a complete one. Unlike most of the other metadata plugins, it only makes use of the book ISBN (10 or 13 digit) to query the biblionet database.
Normally such a plugin can also make use of the title and author info. But for adding printed books entried in calibre (that was my initial motive, remember?) that would be rather tedious, as one would have to manually type every single one of them.
This (:the isbn only feature) is going to change in the next version and the plugin will be able to query metadata based on title or author too.

There is another difference: the plugin makes use of the bookmeta script that acts like a proxy between the plugin and the biblionet database, so the script had to be hosted somewhere. I hosted it at phpfog.com.
If you have some techinal skills, you can host the script wherever you like. Then just edit the plugin file __init__.py, locate the following line,

BASE_URL = 'http://bookmeta.phpfogapp.com/index.php?isbn='

and change the ‘http://bookmeta.phpfogapp.com/‘ to the address of your server.
If not, remain assured that I will host this solution to phpfog for your convenience.

In the next version of the plugin, this need will be eliminated. The plugin will not require this kind of intermediary. But the bookmeta script will stay, as there might be other programs/services that could potentially use it.

If you want to fork the plugin and make your own, head to github and serve yourselves.

Please give some feedback if you decide to use the plugin. It both motivates and helps 🙂

4 thoughts on “A Calibre plugin for Greek book metadata”

While I haven’t looked at your code yet, that’s excellent Niko! I’m not sure how many people will find a need for it, but it doesn’t really matter. I love the spirit and the fact that you went through with it! Kudos.